Spatial and temporal distributions of level ice properties

Abstract

Abstract Sampling matrices were established at three different sites of Van Mijenfjorden, Svalbard. In total, 193 horizontal and 117 vertical sea ice samples were tested in uniaxial compression from early March to early May 2010. Temperature, density and salinity (TDS) were also measured on every core. Additional samples were taken for TDS profiles as well as for thin sections. The variability in strength seemed to be correlated with the salinity variability, the mean value of the brine fraction and possibly the sampling spacing. Both the variability in strength and salinity increased when the brine fraction increased above 0.05, but for a further increase in the mean brine fraction, only the salinity variability increased (not the strength variability). This means that the drainage and localization of brine becomes a key factor for ice strength variability. The variability of the salinity of the horizontal samples was higher than for the vertical samples at the third site and suggests that one level of a typical brine channel spacing was between the diameter of the vertical samples (72 mm) and the length of the horizontal ones (175 mm). The ice growth predicted by Stefan's law fitted the measurements well with a correction factor ω = 0.40. The thin sections revealed that the ice taken on the first two sites was granular up to 30 cm and then columnar. The transition from S2 to S3 ice may have occurred between 45 and 54 cm.